Method of sulphuration



Patented Aug. 12, 1947 METHOD OF SULPHURATION John W. Church, Mount Lebanon, Pa., assignor to Falk & Company, Carnegie, Pa., a corporation of Pennsylvania No Drawing. Application April 14, 1942, Serial No. 438,905

This invention relates to a method of sulphuration and particularly to a method of sulphurating, or vulcanizing by means of sulphur, organic compounds, such as unsaturated thermoplastic resins and fatty acid triglycerides.

When heated with an adequate proportion of sulphur to a reaction temperature within the approximate range of 330 F. to 410 F. unsaturated resins and unsaturated fatty acid triglycerides are susceptible to marked changes by the action of the sulphur. The first effect is one of saturation and during this stage of the sulphuration process the reaction takes place quietly without any profuse evolution of hydrogen sulphide, or marked darkening of the starting material. In other subsequent stages of the reaction, as heating of the reaction mass in the presence of the sulphur is continued, there is a strong evolution of hydrogen sulphide and a marked darkening of the reaction mass. It has been my experience that in the sulphuration of resins and fatty acid triglycerides to secure sulphurated products of various characteristics it is usually desirable to carry the reaction beyond its initial and quiet stage into higher stages in which marked darkening of the reaction mass is usually produced as the reaction proceeds. This is because it is in these later stages that saturation of the initially unsaturated fatty acid triglycerides and resins is completed and substitution and intermolecular linkages in the materials acted upon take place.

It is the object of my invention to provide simple procedure which results in eliminating or greatly decreasing the darkening effect of the sulphuration reaction when carried beyond the stage of simple saturation on unsaturated fatty acid triglycerides and unsaturated resins forming the reaction mass.

It is my discovery applicable to all sulphuration processes in which fatty acid triglycerides, resins, or reaction mixtures composed of both fatty acid triglycerides and resins, are subjected to sulphuration, that darkening of the reaction mass may be eliminated or greatly decreased by using a solution of sulphur rather than sulphur in ground or otherwise finely divided solid state. By employing sulphur in solution and conducting a sulphuration process within the normal range of understood that the same principles apply to the 2 Claims. (01. 106-223) sulphuration of any vulcanizable thermoplastic oil soluble resins and any unsaturated fatty acid triglycerides, I dissolved 10 parts by weight of sulphur in 100 parts by weight of alpha-pinene with heating to about 320 F. I then slowly added to the sulphur solution with agitation 125 parts by weight of crushed 6% limed rosin and parts by weight of kettle-bodied soya bean oil, and raised the temperature to about 350 F.

Within about 15 minutes while holding the reaction mass at that temperature the reaction had proceeded to a stage in which there was a substantial evolution of hydrogen sulphide gas and a marked thickening of the reaction mass. Upon continuing the reaction until the evolution of gas had perceptibly slowed, and then cooling, a high viscosity reaction product was obtained. Upon color comparison with the product obtained by fusing together similar limed rosin and kettlebodied soya bean oil in the same proportions, it was found that the reaction product was not substantially darker than the starting material, both being of about a color 12 on the Gardner-Holdt color scale. A check procedure conducted similarly with limed rosin and kettle-bodied soya bean oil in the same prooprtions and in which sulphur in the same proportion was used, but in which the reaction mass was first heated to a temperature of 350 F. and the sulphur was added in finely divided solid state, showed a darkening to about a color 18 on the Gardner-Holdt color scale.

The same procedure is effective when using as a source of unsaturated fatty acid triglycerides any of the so-called drying and semi-drying oils, either in raw condition or as pretreated by kettlebodying, and when using any of the thermoplastic vulcanizable resins, such as rosin, coumaroneindene resin, petroleum resin, terpene resin, either raw or in'a pretreated condition such as limed or esterified rosin (ester gum), or by hydrogenated o chlorinated rosin, coumarone-indene resin, petroleum resin, or terpene resin.

Any of the less evaporative solvents for the sulphur may be used, but I have found it preferable to use one of the cyclic hydrocarbon solvents; such as the aromatics as exemplified by toluol and benzol, or carbo-cyclic terpene hydrocarbons, such as whole turpentines, or their fractions as exemplified by alpha-pinene, 'dipentene, terpinene and the like.

Further to exemplify my invention, I slowly added parts by weight of ground raw rosin to 8 parts by weight of sulphur dissolved in 100 parts by weight of benzol, and raised the temperature of the batch gradually to about 350 F.

2,425,597 3 4 Heating was continued to a stage in which hyeffectively to inhibit darkening in the reaction drogen sulphide was evolved and the batch thickmass. r ened. Although the rosin was slightly darkened It is to be understood generally that the terms by the sulphuration treatment, the darkening and exemplifications herein used are descripwas much less than is caused by the addition of 5 tive and illustrative rather than restrictive, and

ground sulphur to the startin material. that numerous changes may be made in the com- The above procedure was duplicated en cqupositions embodying my invention, and in the 'marone-indene" resin, diolefih (petroleum) resin procedure by which they are madewhile reand terpene resin, with approximately identical maining within the bounds of my invention as advantage in the prevention of darkening in the defined in the appended claims.

material subjected to vulcanization. Iclaim as my invention: 7 7

Also, I slowly added 100 parts by weight of 1'. The herein described method of producing kettle-bodied linseed oil to a solution of 6 parts light colored sulphurized products from starting by weight of sulphur dissolvedin 5Q parts Q-by material selected from the group consisting of Weight of dipeiitene, and raised" the temperature t unsat atedfatty acid triglycerides, the unof the batch gradually to about 35Q F. V The saturated oil soluble thermoplastic resins, and batch was held at that approximate teinperatiirg 'Ini tuTes'pf'them; by agitatin a starting mato a stage in which hydrogen sulphide Was evolved terial so composed in a prepared reaction bath and the batch thickened. The vulcanized rna composed of elemental sulphur dissolved in a terial was almost imperceptibly darker than beliquid organic solvent therefor while keeping the fore vulcanization. batch composed of the'said reaction bath and The process of in'y invention may be stated as starting material within the approimate stein: the addition "Qf'a starting material selectedfrom pe'ratur'e range of 33,0?F'. 13541;)? and 7 ing the unsaturated "fatty acid iiglycerides, isolated vulcanization of the starting material to a stage $Q r d' but usuallyl'as' they 'ogcur'ihf the in which the batch thickens and 'hydrQgensuIe' dry mgnafhdasemi; drying, 011$, q n mfit ld oil phide is evolved. i i soluble thermoplastic resins, to a vulcanizing 2. The herein described method of producing age'i'it"consistingof sulphuriiil soluti n; thesta tf lightfcol'ored sulphur'ized products from starting ing m ri l' s i g" i ithe ib theiabore'm materials selected from the group consisting of terials taken aloneorasj mi d with each other. the unsaturated fattyacid triglycerides, the un- I have discoveredfthat if the. process is 'consaturated oil soluble thermoplastic resins, and ducted" at atmospheric pressures, the" feature; at mixtures of them, by agitating a starting material sso v ng hiej u hurj ns l ent'hQ l g1 e s pos n, a. e a ed react on ba ho om' the temperature 'oi thevulcanization "reaction is posed of elemental sulphurjdissolved in agcycli'c nOne the -IeSsefieCti ei, Thisjis'because'the'sulhydrocarbon solvent while keeping the batch; phi f so uti n; ifsive a hancei qm x wel fiwi h, m o d the a d action ba h and s ar the starting'."material, either jy'fslowjaddi'tion of, material ithin the approximate temperature the atter or yi' s tation; s e meat her a e f D? F: 1 a ryin il i actiorf massand isdissolved thefrein orfoc'cluded canization or the starting material to afstagle thereby that intensefl'ocalized. reaction is avoided; 40 in Whichthe batch'thickens and hydrogen sulphide is evolved' in spite of the volatilenaturef'of the, solvent. Dfei QHN We H R H sirabl'ythe solvent "is preserved for reuse as by; hoo'ding th'e reactiori' vessel; or by, refluxing the solvent-U I R FERE C S CIT wmpanmn application serial 438-? 5 The followin references are of record in the a m hon orvulcanizat'ion in which darkening of 1 1 g n ab ion, a s' hi ited h' i'mc sio NIT fields-tam of :a m n ral 5 u i ii l o o en h Number Name Date 1 f; a dl nd s h ol ql t sj nhura ia 0 1,590,800 Becker June 29, 1926 the fluen Qt 11 9 1!adw '91.." the a t 'mi 2,111,882 Borglin Mar: 22,1931; i iu e' 's a' inely' ii s e f df is ontem d: 2,186,646 Lincoln et a1. Jan. 9, 1940 The rq tdure, iere di c o e whi hjth u 2,220,843 Johnson Nov. 5,1940 p r e injt 'f rmj uilonl 2,2 2,523 Baconeit al.' Nov."1'1 ,11'f9f31 i h lh l lf i ll fi. f hs 1 m xtu e" Re.'6,'708 Day oat 1911875,

a added o he lph rl'andf he} ac on mas isthhfireated to a temperature at which the reaction takes "place, may; ,fe employed i'fi'r'e? Number action migiture's from which mineral oil is omit- 629,213 ted as wellas t se in" whichit" is included, 15,595

tonnes Partn rs.

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